DESCRIPTION: This investigation will use descriptive and experimental techniques from linguistic theory and L2 acquisition to test hypotheses about the stages by which a learner succeeds in making a phonemic split between two or more native language allophones, and the strategies for training such a split. In the first of two projects, two studies will focus on training native speakers of Spanish to contrast two sounds. In one group, the contrast will be trained in derived environments (those involving a morpheme boundary); in the other group, the contrast will be trained in nonderived environments. The principles of Lexical Phonology predict that acquisition in derived environments will generalize immediately and completely to nonderived environments, but that generalization will not necessarily proceed in the opposite direction, from derived to nonderived environments. These two studies will be replicated with native speakers of Korean learning to contrast two English sounds. In the second project, data will be gathered to analyze the role of native language and target language lexical rules in L2 pronunciation of the Korean rule of /t/-Palatalization and the Spanish rule of Velar Softening. By contrast with post-lexical rules, the prediction is that neither of these lexical rules will interfere with the learning of TL pronunciation.